Process of carbonizing solid bituminous fuel



July 4, 1933.

J. A. PERRY 1,917,196 PROCESS OF CARBONIZING SOLID BITUMINOUS FUEL FiledFeb. 27, 1929 T /9 2\ ul CLL-@um GIS Patented July 4, 1933` UNITEDSTATES PATENT OFFICE JOSEPH A. PERRY, OF SWARTHMORE, PENNSYLVANIA,ASSIGNOR T0 THE UNITED GAS IMPROVEMENT COMPANY, OF PHILADELPHIA,PENNSYLVANIA, A CORPORA- TION 0F PENNSYLVANIA PROCESS' OF CARBONIZINGSOLID BITUMDIOUS FUEL Application filed February 27, 1929. Serial No.343,091.

The present invention relates to thecarbonization of solid bituminousfuel by direct contact with hot gases.

More particularly it relates to the carbonization of such fuel by thecontact of the hot products of combustion produced by the'combustion offuel with an oxygen-containing medium that contains a greaterproportionof free oxygen than does atmospheric air, with the productionof coke and a, mixed gas consisting of coal gas and products ofcombustion relatively low in inert nitrogen.

The object of the invention is to provide an improved method for suchcarbonization.

In general the process includes establishing a continuous orintermittent flow of the bituminous material, one portion of which iscomprised of uncarbonized and partially carbonized fuel in process ofheating and another portion of which is comprised of coke resulting fromthe carbonization in process of cooling, establishing a hot zoneintermediate of the ends of the flow of fuel by heating an intermediateportion, indirectly, by the combustion of other fuel with an oxygencontaining gas that contains a greater proportion of free oxygen thanatmospheric air, and directly, mentioned fuel the resultant hot productsof combustion, passing them from the hot zone through the fuel inprocess of carbonizing to heat it and eifect carbonization, leading offthe resultant mixed coal gas and products of combustion from the fuel,passing a. cooling agent through the coke resulting from thecarbonization to cool it and from thence through the hot zone andthrough the fueI undergoing carbonization to assist in thecarbonization.

The process will be particularly described in its application to adescendin fuel bed and in connection with the attac ed drawing whichforms a part of this specification.

The drawing shows a partial\vertical cross section and elevation ofapparatus chosen for illustration in which my process may be performed.

Referring to the drawing,

1 generally indicates the carbonizing chamber, containing a fuel bed theupper by leading into the first portion of which, indicated as 2, iscomprised ofsolid bituminous fuel undergoing carbonization and the lowerpart of which, indicated as 3, is composed of coke resulting from thecarbonization.

4 is a combustion chamber-provided with the fuel supply means and oxygensupply means 5 and arranged to heat the intermediate section of the fuelbed through the wall 6. The combustion chamber 4 is in communicationwith the fuel bed at a zone intermediate of the ends of the fuel bed.

The carbonizing chamber is provided with the gas off-take 7 leading fromabove the lfresh fuel through the valve 8 to the wash- 10 is the asoff-take from the wash-box to a place o storage, not shown.

The off-take 7 may also be connected through the valvel 11 to the inputside of the circulating means 12 (a fan, as shown for illustration). Theoutput side of the fan is connected by connection 13 to the base of thefuel bed. eans for the continuous discharge of coke may be provided asfor instance the travelling grate 14 which discharges to the hopper 15.

eans for continuous fuel may be provided charger indicated at 16.

17 is a steam supply means.

In operation fresh fuel such as bituminous coal, lignite, etc., is fedto the top of the fuel bed by .the charger 16 and cooled coke removedfrom its base by the grate 14.

Fuel and an oxygen-containing medium containing a greater proportion offree oxygen than does atmospheric air are admitted to the combustionchamber 4 and partially burned therein, heating the mid-section of thefuel bed indirectly through the wall 6. The products of combustion passfrom the combustion chamber into the mid-section of the fuel bed heatingit directly and pass upward through the fuel in the upper portion of thefuel bed effecting its carbonization and distilling olf its volatilematerial. The mixed coal gas and products of combustion give up theirheat in contact with the fresh fuel in the upper portion'of the fuel.bed and charging of fresh if desired as the issue from the top of thefuel bed relatively cool. A portion of the mixed gas passes throughconnection 7 and valve 8 to the wash-box, the remainder is drawn throughvalve ll by the fan 12, passed by connection 13 to the base of the fuelbed and forced upward through the coke, cooling the coke in the passage.The mixed gas then passes through the highly heated zone and is heatedtherein and passes upward through the uncarbonized fuel above to assistin its carbonization.

Instead of recirculating the mixed gas to cool the coke, all of themixed gas may be led directly to the wash-box and a small amount ofsteam, sufficient to cool the coke, may be admitted at 17 and passedupward through the fuel bed or steam may be mixed and recirculated withthe gas produced The fuel introduced with oxygen, to the combustionchamber may be pulverized coal, oil, tar or gas. Preferably suhcientoxygen is introduced for its partial combustion only, therebymaintaining a low proportion of incombustible constituents in theresultant combustion gases.

The exact composition of the final mixed gas will depend, among otherthings, on the fuel introduced to the combustion chamber. In the case ofoil or refinery oil gas, partial combustion with oxygen can be regulatedto furnish combustionv products containing considerable amounts ofhydrocarbons as well as carbon monoxide and hydrogen and the combustionproducts may have a rela- -tively high calorific value.

If the fuel supplied to the combustion chamber is pulverized coal, thesupply of this fuel and the oxygen supply may be regulated to effect thepartial or total carbonization of the pulverized fuel by combustion of apart of it.

As the combustion products are passed through the fuel bed, the fuel bedwill retain the partially carbonized pulverized fuel and itscarbonization will be completed therein. If the carbonization iscompleted in the combustion chamber, the fuel bed will retain theresultant coke which will be cooled and discharged with the cokeproduced in the fuel bed.

The operations of carbonizing by the hot products of oxygen combustionand the cooling of the coke may be simultaneous and continuous, or theymay be alternated if desired.

The fuel bed may be in continuous descent as illustrated or the descentmay be intermittent, due to periodic charging of fresh fuel and removalof coke.

While I may prefer to employ a fuel bed in the practice of my invention,it is also applicable to the carbonization of a stream of pulverizedfuel. A descending flow of pulverized fuel may be established in theretort by feeding pulverized fuel at the top and removing coke at thebottom. The mid-section of this stream of fuel may be heated indirectlyby the combustion of other fuel with oxygen in the combustion chamberand directly by passing the resultant hot products of combustion intothe fuel stream and upward against the downward fall of the fuel,heating and carbonizing the fuel in the upper portion of the retort. Acooling agent, as mixed products of oxygen combustion and coal gas orsteam, may be introduced at the base of the retort to cool the coke andto be heated in the mid-section of the retort and assist in thecarbonization above.

In any of the above methods all of the combustion need not all takeplace in the combustion chamber, a portion may take place in thecarbonizing chamber, all of the combustion is not necessarily confinedto the fuel supplied to the combustion chamber, a portion of the fuelfed to the carbonizing chamber may also be burned.

I claim:

1. A continuous process of carbonizing solid bituminous material withthe production of coke and combustible gas, which comprises providing asubstantially Vertical column of solid bituminous material and feedingit downwardly longitudinally thereof into a closed space, carbonizingthe material in said column by burning secondary fuel other than thematerial in said column in said space with an oxygen-containing gashaving a greater proportion of free oxygen than atmospheric air,transferring heat to an intermediate portion of said column externallythereof from the products of the combustion but out of contacttherewith, passing all the products of the combustion upwardly throughsaid column in contact with the material therein, discharging the cokefrom said space, withdrawing the relatively cool mixture of coal gas andproducts of cumbustion from the column, and recirculating a portion ofsaid relatively cool mixture of coal gas and products of combustionthrough the column to cool the coke and to become heated in the columnand to transfer heat to carbonize the on-coming bituminous material.

2. A continuous process of carbonizing solid bituminous fuel, whichcomprises establishing a substantially vertical descending column ofsolid bituminous fuel, burning secondary fuel other than the material insaid column with an oxygen-containing gas having a greater proportion offree oxygen than atmospheric air adjacent the middle portion of saidcolumn, admitting all the products of the combustion of the secondaryfuel to said column, carbonizing the material in the intermediateportion of said fuel column by said burning of secondary fuel and bysaid products of combustion, causing products of combustion to ascendthrough the descending fuel column, taking off a portion of the gas soformed, and recirculating the remainder of the gas so formed from thebottom through the entire fuel column.

3. A continuous process of carbonizin bituminous fuel according to claim2 in wxich steam is passed to ether with the recirculated gas up througthe entire fuel column.

4. A continuous process of carbonizing solid bituminous material withthe production of coke and combustible gas, which process comprisesfeeding asubstantially vertical column of solid bituminous materialdownward longitudinally thereof into a closed space, carbonizing thematerial in said co1- umn by continously burning pulverized coal in saidspace with an oxygen-containing gas that contains a greater proportionof free oxygen than atmospheric air in such a manner that the solidproducts of said combustion fall into the lower part of said column,transferring heat to an intermediate portion of said column externallythereof from the products of the combustion but out of contacttherewith, passing the Huid products of combustion upwardly through saidcolumn in contact with the material therein, discharging the coke fromsaid space, and leading olf mixed coal gas and products of combustionfrom the upper part of the column.

5. A contlnuous process of carbonizing solid bituminous material withthe production of coke and combustible gas, which comprises feeding asubstantially vertical column of solid bituminous material downwardlylongitudinally thereof into a closed space, carbonizing the material insaid column by continously burning secondary fuel other than the cokeproduced by said process in said space with an oxygen-containing gasthat contains a greater proportion of free oxygen than atmospheric air,transferring heat to an intermediate portion of said column externallythereof from the products of the combustion but out of contacttherewith, passing all the products of the combustion upwardly throughsaid column in contact with the material therein, dischargin the cokefrom said space, leading of mixe coal gas and products of combustionfrom the upper part of the column, and recirculating a portlon of saidmixture of coal gas and products of combustion through the entire columnof fuel together with steam.

JOSEPH A. PERRY.

